Duplex bag

ABSTRACT

The invention concerns a method for making packaging bags ( 1 ) with a double wall ( 31; 31 ), characterized in that it comprises steps which consist in: unwinding a first packaging sheet ( 31 ) wherein a window is cut out or precut; unwinding a second packaging sheet ( 32 ) wherein another window is cut out or precut; applying a closure assembly ( 5 ) on the moving packaging sheet, perpendicular to a window; fixing the closure assembly on the packaging sheet; fixing the two packaging sheets one on the other to form a double wall, said sheet being then formed into a packaging bags ( 1 ).

OVERALL TECHNICAL FIELD

The invention relates to the field of packaging sachets.

Numerous packaging sachets and numerous systems for manufacturing themhave already been proposed.

For thin sachets, usually flat, in a filled state, the known means giveoverall satisfaction. In this case, the sachets are generally made fromtwo flat sheets welded together along three sides and bearing means forsealing, for example complementary male/female sections at the openingof the sachets.

On the other hand until now, the making of sachets for bulky items,irrespective of their nature, has proved unsatisfactory, despitenumerous studies in this very specific field.

In particular, such sachets often require relatively thick walls, and itis not easy to attach means for sealing to such walls.

This applying of the means for sealing is all the more delicate when themeans for applying are not located at the opening of the packagingsachet, but on a surface of the sachet.

We have diagrammatically illustrated in the annexed FIG. 1 a knowntechnique for manufacturing sachets comprising means for sealing 5attached to a wall 3 of the packaging sachet 1, and not at the opening 2of the packaging sachet.

The means for sealing 5 are welded or stuck to points 6 on the frontwall 3 of the bag 1.

The points of application are made on the means for applying 7 of themeans for sealing 5. These means for applying 7 comprise films, forexample made in plastic.

The means for sealing 5 can also comprise means 8 forming runnersfacilitating the opening and closing of the means for sealing 5.

Examples of such known bags are disclosed and illustrated in documentsU.S. Pat. No. 4,335,817 and EP 0 843 636.

The sachets, according to the prior art, however, compriseinconveniences.

Notably, the points of application 6 are not entirely sound.

Such sachets do not envisage the applying of means for applying onsachets comprising double-layer walls, that meaning double ply bags.

PRESENTATION OF THE INVENTION

The invention proposes to overcome these inconveniences.

For this reason the invention proposes a method for manufacturingdouble-ply packaging sachets characterised in that it comprises thestages according to which:

-   -   we feed a first packaging sheet on which we cut out a window        patch;    -   we feed a second packaging sheet on which we cut out another        window patch;    -   we attach a set of seals to a fed-through packaging sheet,        perpendicular to the window patch;    -   we attach the set of seals to the packaging sheet;    -   we attach the two packaging sheets to each other to form a        double ply sheet, this sheet then being formed into a packaging        sachet.

The invention is advantageously completed by the followingcharacteristics taken singly or in any technically possible combination:

-   -   we attach the set of seals between the two packaging sheets, so        that the means for applying the set of seals are incorporated        between the two packaging sheets;    -   we attach the set of seals to one of the two packaging sheets,        the double ply formed by the other packaging sheet not covering        the means for applying the set of seals;    -   we weld the means for applying the set of seals to the packaging        sheet;    -   we stick the means for applying the set of seals to the        packaging sheet;    -   we cut out at least the window patch intended for the external        wall of the double ply sachet with a pre-cut dotted line so that        the wall of the sachet is capable of forming a seal covering the        set of seals on the front of the sachet and being of        tamper-proof type prior to the first opening; and    -   we attach an adhesive strip opposite the window patch of the        external wall, this strip thus constituting a tamper-proof        element to be stripped off upon the first opening of the sachet.

The invention relates to sachets produced by this method as well as themachines for implementing the method according to the invention.

PRESENTATION OF THE FIGURES

Other characteristics, purposes and advantages of the invention will berevealed through the description that follows which is clearlyillustrative and non restrictive and which must be read in relation tothe annexed drawings in which:

FIG. 1, already evoked, diagrammatically represents a bag according tothe prior art comprising an opening on one single ply wall;

FIG. 2 diagrammatically represents a front view of a double ply bagcomprising an opening on one wall of the bag;

FIG. 3 represents a first method for applying an opening and a set offastening between the two sheets of a wall of a double ply bag;

FIG. 4 represents another method for applying means for sealing on adouble ply bag;

FIG. 5 represents an embodiment where a packaging sachet comprises onits surface means for sealing a pre-cut window patch forming a“tamper-proof strip”;

FIG. 6 represents an embodiment where a packaging sachet comprises onits surface means for sealing an adhesive strip forming a tamper-proofstrip;

FIG. 7 represents an embodiment in which openings are formed on theupper part of the sachet once filled and thus allows to form a griphandle;

FIG. 8 represents an embodiment according to which the means forgripping are formed by straps attached to the upper part of thepackaging bag; and

FIG. 9 diagrammatically represents a machine assembly allowing to attachmeans for sealing and to manufacture double ply bags.

DETAILED DESCRIPTION OF THE INVENTION

As previously indicated the invention relates to the producing ofre-sealable sachets using automatic machines, these sachets comprising adouble ply wall.

This invention can apply as much to horizontal feed through automaticsachet production machines as to vertical feed through automatic sachetproduction machines.

Furthermore, the invention applies as much to automatic sachetproduction machines with filling during a stage subsequent to theproduction and possibly geographically separate from the production siteas to production machines with filling and sealing—of “FORM, FILL, SEAL”(FFS) type—on a single site and in successive stages.

Thus the invention preferably and advantageously applies to FFS typevertical feed through machines.

We have diagrammatically represented in FIG. 2 a bag 1 intended toreceive thick contents, which will be for example inserted into the bag1 by the opening 2, this bag 1 principally comprising two walls 3 and 4.

Such a sachet 1 is formed according to a known technique by the foldingon itself of a packaging sheet so as to form a bag. The bag 1 comprisesfor example, but not obligatorily gussets 9 on its sides. We canadvantageously refer to the applicant FR 2 758 761 in order tounderstand the forming and producing of such sachets.

We have designated the front wall of the bag 1 with 3 and the rear wallof the bag 1 with 4.

The front wall 3 comprises a set of seals 5 this set of seals 5comprising for example but not obligatorily means 8, facilitating theopening and the closing of the means for sealing the set 5. The means 8will be for example formed by a runner that can be moved along knowncomplementary sealing sections.

The set of seals 5 can also comprise means for sealing that do notcomprise male/female type complementary sealing sections.

The set of seals can comprise a U-shaped or W-shaped film, or any knownshape.

Additionally, the set 5 can comprise a film covering the means forsealing, and allowing to form a “tamper-proof” type film. The film isopened upon the first opening of the sachet by the tearing of a line ofweakness made in the film material, this line of weakness can comprisedotted lines.

The walls of sachet 1 comprise two pieces, called plies. We havedesignated in FIG. 2 the exterior ply of the wall 3 with 31 and theinterior ply of the wall 3 with 32. We have also designated the exteriorply of the wall 4 with 41 and the ply of the wall 4 with 42, the ply 42being on the inside of the sachet 1.

FIG. 3 diagrammatically represents the attaching the set of seals 5 tothe inside of the double ply wall 3.

According to the invention, the set of seals 5 comprises means forapplying 7. These means for applying 7 will be for example formed byside films, in whatsoever material. The side films can thus be composedof typical material, but also of paper or carton type material.

According to the invention, these means for applying 7 are attached atpoints 6 to the wall of the bag 1.

The points of application 6 comprise, according to a first embodimentrepresented in FIG. 3, a first point of application 61 which attachesthe means for applying 7 to the ply 31, and a second point ofapplication 62 attaching the means for applying 7 to ply 32.

This embodiment has the advantage over the embodiment of the prior artof allowing the very sound attachment of the set of seals 5 to a doubleply bag.

In FIG. 3, we have represented a set of seals 5 comprising means formingmale/female type complementary sections 10 as well as means forming therunner 8 allowing to easily open and close these means for sealing 10.

The runner can be in either metal or plastic.

Other means for sealing can obviously be attached to such a wall 3, forexample means that do not comprise sealing runners, or means for sealingthat do not comprise complementary sections.

FIG. 4 represents another embodiment for the attachment of a set ofseals 5 to a wall 3.

According to this embodiment, the wall 3 comprises points of application6 which are not overlaid.

Indeed, the means for applying the set 5 are attached to ply 31 by apoint of application 61, even though they are not attached to ply 32 ofthe wall 3.

In the embodiment represented in FIG. 3, the ply 32 does not haveexactly the same dimensions as ply 31. In other words, the cut-outwindow patch in ply 32 allowing a user to gain access to the inside ofthe bag has greater dimensions than the window patch pierced in ply 31of the bag 1, the latter window patch allowing access to means forsealing the bag.

The ply 32 is attached to ply 31 by points of application indicated by63 in FIG. 4.

In FIG. 4, we have represented means for sealing that do not compriseopening and closing runners. The means for sealing comprise male/femaletype complementary sections, but an alternative to this embodimentcomprising means for sealing that do not have such sections isconceivable.

FIG. 5 represents an alternative to the embodiment represented in FIG.3. According to this alternative, the ply 31 does not comprise anopening allowing direct access for the user to the set of seals 5.

According to this alternative, the window patch 33 is pre-cut out of theply 31, without being totally open. Thus, the means for sealing 5 arenot accessible from the outside of the sachet. The pre-cut window patch33 thus constitutes a “tamper-proof” type seal allowing to indicate tothe user that the sachet has never been opened.

Come the first opening of the sachet 1, the user will cut thetamper-proof window patch 33 along the dotted line on the ply 31. Forthis reason, the dotted line constitutes a line of weakness in the ply31 allowing to easily open the tamper-proof window patch 33.

The pre-cut dotted line can be of another type, for example a line ofweakness with a lesser thickness in the case for example of plies madein plastic.

In FIG. 5, the tamper-proof window patch is located on the ply 31. Wecan also envisage placing a tamper-proof window patch on the ply 32,retaining or not the tamper-proof type window patch on the ply 31.

FIG. 6 represents another alternative of the sachet represented in FIG.3, according to which the tamper-proof window patch is no longerconstituted of a pre-cut window patch on the ply 31, but is constitutedof an adhesive strip 33 which is stuck to the perimeter of the windowpatch open in the ply 31, the stickiness being made via the points ofapplication 64 located on the exterior of the sachet.

This relatively strong stickiness allows to form a perfect tamper-prooftype seal perpendicular to the set of seals 5.

This adhesive strip 33 can be constituted of a plastic type material.

As in the alternative represented in FIG. 5, this adhesive strip canalso be stuck to the wall on the inside of the bag on the ply 32. Thechoice of an adhesive strip on the ply 31 and/or 32 is madeindependently from each other.

We can also for example place an adhesive strip, as represented in FIG.6, on a tamper-proof window patch of the type represented in FIG. 5.

FIG. 7 represents a bag according to the invention in which we havepierced two window patches 10 in the upper part allowing to form meansfor gripping so as to carry the packaging bag.

FIG. 8 represents an alternative according to which the means forgripping are constituted of straps 11.

The attaching of the straps or cords 11 can be ensured via sticking orvia stringing said straps in holes made in the upper part of the sachet.The stringing is followed by a stage in which we stick on the upper partof the sachet or we tie the straps in the purposely made holes.

Alternatively, the bag could only comprise a single strap or cordforming a handle.

The walls of the packaging bag can be indiscriminately made in plasticmaterial, paper or carton type material. The walls can for example beconstituted of an interior ply in a material, the exterior ply being inanother material.

FIG. 9 diagrammatically represents a machine allowing to perform themethod of forming and manufacturing sachets according to the invention.

A first packaging sheet 31 is reeled off a paper roller 92.

In stage 94, a window patch is pierced or pre-cut.

At point 95, a set of seals 5 is attached perpendicular to the piercedor pre-cut window patch.

In stage 96 we weld or stick the means for applying the set of seals tothe perimeter of the pierced or pre-cut window patch. The stage 96 canfor example be carried out thanks to the feeding through of the sheetbetween two feed-through rollers visible in FIG. 9.

We are mindful that the set of seals is of any type and that it does ordoes not comprise a runner.

Simultaneous to the feeding through of the sheet 31, a packaging sheet32 is reeled off the roller 91.

In stage 93 we pierce or pre-cut a window patch of similar size or of adifferent size to the pierced or pre-cut window patch at point 94,according to the embodiment that we wish to obtain (see FIGS. 3 and 4).

The sheet 32 continues to be reeled off so as to simultaneously arriveat point 97 with the sheet 31. At this stage, we back the sheet 32 tothe sheet 31 so as to obtain a double ply packaging sheet.

The piercing or pre-cutting of the window patches at stages 93 and 94 issynchronized, so that the window patches lie perpendicular to each otherwhen they arrive at point 97. The stage 97 can for example be carriedout thanks to the feeding through of the sheets between two feed-throughrollers visible in FIG. 9.

We envisage starting from point 98 methods and machines for lateralwelding so as to form the bag, with or without side gussets, its fillingbefore sealing the upper opening of the bag.

Stage 98 can also comprise the piercing of the means for gripping ofhandle type or the attaching of straps and cords forming means forgripping. It can be carried out at a different site than that of thestages represented in FIG. 9, at times near or relatively distant.

We are mindful that the diagram in FIG. 9 does not whatsoever assume theposition of the machine. For example, it could be a vertical orhorizontal feeding through and that the attaching of the set of seals 5can be carried out longitudinally or transversally to the feedingthrough of the packaging sheet 31.

1. Method for manufacturing double ply (31, 32) packaging sachets (1)characterised in that it comprises the stages according to which: wefeed a first packaging sheet (31) on which we cut out or pre-cut awindow patch; we feed a second packaging sheet (32) on which we cut outor pre-cut another window patch; we attach a set of seals (5) to afed-through packaging sheet, perpendicular to a window patch; we attachthe set of seals to the packaging sheet; we attach the two packagingsheets to each other to form a double ply sheet, this sheet then beingformed into a packaging sachet (1).
 2. Method set forth in claim 1,characterised in that we attach the set of seals (5) between the twopackaging sheets (31, 32), so that the means for applying the set ofseals is incorporated between the two packaging sheets.
 3. Method setforth in claim 1, characterised in that we attach the set of seals toone of the two packaging sheets (31, 32), the double ply formed by theother packaging sheet not covering the means for applying the set ofseals.
 4. Method set forth in one of claims 1 to 3, characterised inthat we weld the means for applying the set of seals to the packagingsheet.
 5. Method set forth in one of claims 1 to 3, characterised inthat we stick the means for applying the set of seals to the packagingsheet.
 6. Method set forth in one of claims 1 to 5, characterised inthat the times of cutting out window patches are synchronised so thatthe window patches lie opposite each other come the subsequent joiningof the packaging sheets in order to form the double ply sheet.
 7. Methodset forth in one of claims 1 to 6, characterised in that we cut out atleast the window patch intended for the external wall (31) of the doubleply sachet with a pre-cut dotted line, so that the wall of the sachet iscapable of forming a seal covering the set of seals on the front of thesachet and being of tamper-proof type prior to the first opening. 8.Method set forth in one of claims 1 to 7, characterised in that we cutout the window patch intended for the internal wall (32) of the doubleply sachet with a pre-cut dotted line, so that the interior wall of thesachet is capable of forming a seal covering the set of seals on theinside of the sachet and being of tamper-proof type prior to the firstopening.
 9. Method set forth in one of claims 1 to 8, characterised inthat we attach an adhesive strip (33) opposite the window patch of theexternal wall, this strip thus constituting a tamper-proof element to bestripped off upon the first opening of the sachet.
 10. Method set forthin one of claims 1 to 9, characterised in that we form packaging sachetsby folding the double ply sheet on itself.
 11. Method set forth in oneof claims 1 to 10, characterised in that we fold the double ply sheet inorder to obtain gussets (9) on the sides of the sachet.
 12. Method setforth in one of claims 1 to 11, characterised in that we bring the setof seals transversally in relation to the feed through direction of thepackaging sheet.
 13. Method set forth in one of claims 1 to 11,characterised in that we bring the set of seals longitudinally inrelation to the feed through direction of the packaging sheet. 14.Method set forth in one of claims 1 to 13, characterised in that the setof seals comprises a runner (8) facilitating the opening and the closingof the means for sealing the set.
 15. Method set forth in one of claims1 to 14, characterised in that the set of seals comprises complementarysealing sections.
 16. Method set forth in one of claims 1 to 15,characterised in that the set of seals comprises a sealing film locatedtowards the outside or inside of the sachet, and covering the means forsealing the set of seals, so that said film constitutes a tamper-proofelement prior to the first opening of the sachet.
 17. Method set forthin claim 16, characterised in that the sealing film comprises a line ofweakness capable of being torn upon the first opening of the sachet. 18.Method set forth in one of claims 1 to 17, characterised in that atleast one packaging sheet is a sheet made in plastic material. 19.Method set forth in one of claims 1 to 18, characterised in that atleast one packaging sheet is a sheet made in paper type material. 20.Method set forth in one of claims 1 to 19, characterised in that atleast one packaging sheet is a sheet made in carton type material. 21.Method set forth in one of claims 1 to 20, characterised in that thedouble ply packaging sheet is sent to a method for forming and fillingof FFS type.
 22. Method set forth in one of claims 1 to 21,characterised in that we make an opening forming a handle at the top ofthe packaging sachet.
 23. Method set forth in one of claims 1 to 21,characterised in that we attach at least a grip strap forming a handleat the top of the packaging sachet.
 24. Double ply packaging sachetcharacterised in that it comprises: a first packaging sheet (31)comprising a window patch; a second packaging sheet (32) comprisinganother window patch; a set of seals (5) attached to a packaging sheet,perpendicular to a window patch; the two packaging sheets being attachedto each other so as to form a double ply sheet, this sheet forming saidpackaging sachet (1).
 25. Sachet set forth in claim 24, characterised inthat the set of seals (5) is located between the two packaging sheets,so that the means for applying the set of seals are incorporated betweenthe two packaging sheets.
 26. Sachet set forth in claim 25,characterised in that the set of seals is attached to one of the twopackaging sheets (31), the double ply formed by the other packagingsheet not covering the means for applying the set of seals.
 27. Sachetset forth in one of claims 24 to 26, characterised in that at least thewindow patch intended for the external wall of the double ply sachetcomprises a pre-cut dotted line, so that the wall of the sachet forms aseal covering the set of seals on the front of the sachet and being oftamper-proof type prior to the first opening.
 28. Sachet set forth inone of claims 24 to 27, characterised in that the window patch intendedfor the internal wall of the double ply sachet comprises a pre-cutdotted line, so that the interior wall of the sachet forms a sealcovering the set of seals on the inside of the sachet and being oftamper-proof type prior to the first opening.
 29. Sachet set forth inone of claims 24 to 28, characterised in that it comprises an adhesivestrip on the external wall of the sachet and covering the set of sealsof the sachet, this adhesive strip constituting a tamper-proof elementprior to the first opening of the sachet.
 30. Sachet set forth in one ofclaims 24 to 29, characterised in that it comprises gussets on itssides.
 31. Sachet set forth in one of claims 24 to 30, characterised inthat the set of seals comprises a runner facilitating the opening andthe closing of the means for sealing the set.
 32. Sachet set forth inone of claims 24 to 31, characterised in that the set of seals comprisescomplementary sealing sections and/or a runner.
 33. Sachet set forth inone of claims 24 to 32, characterised in that the set of seals comprisesa sealing film located towards the outside or inside of the sachet, andcovering the means for sealing the set of seals, so that said filmconstitutes a tamper-proof element prior to the first opening of thesachet.
 34. Sachet set forth in claim 33, characterised in that thesealing film comprises a line of weakness capable of being torn upon thefirst opening of the sachet.
 35. Sachet set forth in one of claims 24 to34, characterised in that it comprises at least one packaging sheetwhich is a sheet made in plastic material.
 36. Sachet set forth in oneof claims 24 to 35, characterised in that it comprises at least onepackaging sheet which is a sheet made in paper type material.
 37. Sachetset forth in one of claims 24 to 36, characterised in that it comprisesat least one packaging sheet which is a sheet made in carton typematerial.
 38. Sachet set forth in one of claims 24 to 37, characterisedin that it comprises an opening on its upper part forming a grip handle.39. Sachet set forth in one of claims 24 to 37, characterised in that itcomprises at least a strap on its upper part forming a grip handle. 40.Sachet set forth in claim 39, characterised in that the strap is of cordtype.
 41. Machine for manufacturing double ply packaging sachetscharacterised in that it comprises: means (92) capable of feedingthrough a first packaging sheet (31) and means (94) capable of cuttingout or pre-cutting a window patch; means (91) capable of feeding througha second packaging sheet (32) and means (93) capable of cutting out orpre-cutting a window patch; means (95) capable of attaching a set ofseals to a fed-through packaging sheet, perpendicular to the windowpatch; means (96) capable of attaching the set of seals to the packagingsheet; means (97) capable of attaching the two packaging sheets to eachother in order to form a double ply sheet, and means for forming thissheet into a packaging sachet.
 42. Machine set forth in claim 41,characterised in that the means for applying (95) the set of seals aretransversally fed through in relation to the feed-through direction ofthe packaging sheet.
 43. Machine set forth in claim 41, characterised inthat the means for applying (95) the set of seals are longitudinally fedthrough in relation to the feed-through direction of the packagingsheet.